590  Standardization  of  Medicinal  Products.  {Am-^'^m- 
Without  vivisection  such  results  could  scarcely  have  been  ob- 
tained. The  dog,  the  horse,  the  cow  and  the  goat  contribute  to  this 
valuable  therapeutic  agent.  The  part  taken  by  the  dog  is  that  of 
test  animal  to  determine  whether  the  active  agents  are  present,  since 
no  known  chemical  test  will  show  whether  they  are  present  in  an 
active  form.  The  dog  is,  therefore,  no  less  essential  in  the  cycle 
of  operations  than  the  other  animals  employed.  There  is  no  ap- 
parent reason  why  the  dog,  especially  the  stray,  which  spreads  dis- 
ease, contracts  and  transmits  rabies,  kills  sheep  and  is  rarely  useful, 
should  be  protected,  while  an  open  season  exists  for  deer,  quail  and 
trout,  and  there  is  no  closed  season  for  many  animals  more  deserv- 
ing of  protection. 
The  animals  mostly  used  in  pharmacologic  experiments — vivi- 
section, if  you  please  to  call  it  that — are  the  frog,  mouse,  rat, 
guinea  pig,  rabbit,  dog,  cat  and  monkey.  Of  these,  the  frog  owes 
its  value  to  the  fact  that  being  a  cold-blooded  animal,  its  isolated 
tissues  survive  a  considerable  time  and  can  therefore  be  used,  for 
example,  for  the  study  of  muscular  contraction  and  the  function 
of  the  nerves.  The  guinea  pig,  rat,  mouse  and  rabbit  are  chiefly  of 
value  for  inoculation  experiments ;  while  the  cat,  dog  and  monkey 
are  useful  particularly  for  experiments  on  the  brain,  central  nervous 
system  and  circulatory  system. 
The  dog  is  especially  valuable  in  nutrition  and  digestion  experi- 
ments because  of  its  diet,  which  is  as  omnivorous  as  that  of  man. 
For  many  purposes  no  other  animal  can  be  used  on  account  of  the 
size  of  the  organs  and  the  convenience  of  handling.  For  blood 
pressure  experiments  in  studying  the  heart  tonics  of  the  digitalis 
series,  standardizing  extracts  of  the  pituitary  and  suprarenal  glands, 
testing  the  efficiency  of  hemostatics  and  blood-coagulating  agents, 
standardizing  hypnotics,  such  as  cannabis  indica,  chloral,  chloretone 
and  similar  substances,  no  other  animal  is  so  well  adapted  and  from 
no  other  animal  can  the  results  be  transferred  directly,  almost  with- 
out alteration,  to  man. 
Where  pain  would  accompany  the  experiment  and  when  this 
point  is  not  the  subject  of  the  experiment,  a  preliminary  anesthesia 
with  chloretone  is  usually  applied.  This  general  anesthetic  can  be 
given  internally  by  mouth  and  is  often  so  used.  Complete  anesthesia, 
recognized  by  the  absence  of  reflex  when  the  pupil  is  touched,  re- 
sults in  a  half  hour.   Anesthesia  remains  complete,  when  the  proper 
